That's a really good question, and one that divides photographers.

There are genuine advantages to both, and many people with cameras like the RX100 IV mostly use the rear screen.

The electronic viewfinder, EVF, isn't there because the image is inherently higher quality.

Your rear LCD is larger and often looks sharper. It's useful because of how you shoot.

The EVF gives you several advantages.

Stability. Pressing the camera against your face creates a third point of contact.

Both hands plus your forehead, making it much easier to keep the camera steady.

This can noticeably reduce blur in lower light.

Bright sunlight. On a sunny day, the rear screen can become difficult to see, even at maximum brightness.

The EVF remains clear because it's shielded from ambient light.

Concentration. Looking through the EVF blocks out distractions around you, making it easier to compose carefully.

Battery life. Depending on settings, using the EVF can sometimes be a little more power efficient than the rear screen, though the difference isn't...